Depth sounding apparatus



Oc't. 19, 1937. R. L. WILLIAMS DEPTH SOUNDING APPARATUS Filed Nv. 11, 1952' INVENToR Rami-'R7' L. WML/AM: gzfww/ `ATToRNr--Yv v Patented. Oct. 19, 1937 nnr'rn soUNnnvG Arrmrvs Robert Longfellow Williams, Newton, Massl, as-

signor to Submarine Signal Company, Boston,

Mass., a corporation of Maine Appiimion November 11, 1932, serii No. 642,271

2 Claims.

The present invention relates to the art of depth sounding and in particular tothe method in which a compressionalwave signal is emitted when a rotating indicator is in a zero position and the 5 wave reected from the object whose distance is to be measured is received on a receiver and/made to operate the indicator.

In this system the operation o1' the indicator upon receipt of the echo signal produces an indication on a scale or a chart which indicates the depth. In systems of this nature it has been common practice to use an impact device striking a diaphragm for producing the sound waves. When an impact signal is used it has been the 1.3 custom in one type of depth sounding apparatus to retract the impact striker by an electromagnet or solenoid against the action of a spring and to release the striker either mechanically or electrically so that it will strike the diaphragm when the moving indicator is passing by the zero position on the scale. It has been found that in such types of depth Sounders it is sometimes difiicult to avoid a double blow of the impact producing means since quite frequently, after the rst sound impact has been produced by a hammer striking a diaphragm, a second blow would follow shortly dle to the bouncing of the hammer on the diaphragm.

The purpose of the present invention is to avoid the second blow of the hammer or striking element on the diaphragm of the impact device. In prior systems this has in part been accomplished by the use f so-called buier springs which are deected by the hammer and are given suiicient tension so that when the impact element has once struck the diaphragm and bounced from it, it will not have suicient kinetic energy to force the springs downward so that the diaphragm can again be struck. While this system has proved successful there is a certain amount of difculty in maintaining a constant and uniform operation and it frequently occurs that, after the installation has been operating for a short time, the adjustment on the springs becomes such that its purpose is not accomplished. In addition to this, the springs which are used to prevent a second blow on the diaphragm of the impact oscillator also act to hinder the full force of the i'lrst blow so that a little energy must bedissipated by the springs in order for them to accomplish their purpose. It should also be noted that the buier spring itself is energized under the movement of the impact element and therefore as the impact element recedes in the opposite direction from the blow a 4certain amount of energy is imparted from the buer springs to the impact element.

Th'ese disadvantages are avoided in the present invention wherein immediately after the impact element strikes the diaphragm the current is ap- 5 plied to the electrical operating mechanism to retract the impact element before a second blow can be delivered. If desired, the buffer spring can alsobe employed and the two means can be used in conjunction to prevent a double blow on the 10 I diaphragm.

The system will be more iully described in connection with the specification given below and the drawing schematically showing the complete system. 15

In the figure, the impact oscillator is indicated at I and the rotating disc at 2, carrying lan indicator 3. A constant speed motor may be employed to drive the disc 2 but other appropriate systems may also be used in which the operation of the 20 system may be intermittent.

The indicator 3 is operated through a receiving circuit not shown in the drawing which in the usual manner is operated by the sound waves picked up by a microphone or hydrophone. The '25 disc 2 is rotated on the same shaft l with the cam 5 which operates the spring contacts 6 and l. The spring contacts 6 and i are mounted on an arm 8 which is pivoted at a point 9. The arm 8 at its lower end works through the roller I0 on 30 the cam II which is mounted on the shaft I2. Cams II, I3, I2 and I5 are all mounted on the shaft I2 and driven through the gear system I 6 and I'I by the reduction gears I8 and I9 which in turn are operated by the shaft d. The cams I I, 35 I3, I4 and I5 are driven at a considerably lower speed than the Acam 5, the reason for which will appear later.

The impact oscillator I has a diaphragm 20 which may be exposed to the water or in con- 40 tact with the wall of a vessel. Operating against the diaphragm 20 is the impact element or hammer 2| which works up and down in a solenoid 22. When the solenoid 22 retracts the impact element 2l, the spring 23 is thereby com- 45 pressed and when the current in the solenoid is broken the impact element 2| is released and allowed to strike the diaphragm. The solenoid 22 is energized from the power supply 24 and its operation 4is controlled by the system of cams 50 comprising cams 5, I3, I4 and I5. The purpose of cams I3, I4 and I5 is to introduce sucient resistance in the circuit so that when the cam 5 ultimately opens the contacts 6 and l, very little current will-be iiowing when the circuit is 55 broken. This is accomplished by means of the t resistances 25, 25 and 21. These resistances are placed in series with one side of the line and the contacts 28. 29 and 30 serve to cut out these resistances when they are closed, the contact 30 cutting out the resistance 21, the contact 23 cutting out both resistances 25 and 21 and contact 28 cutting out all three resistances. The resistance 3| is always in series with the contacts and 1, and regulates the current in'the circuit.

When the roller 32 drops from the high part of the cam I5, the contact 30 is made and in a similar fashion when the rollers 33 and 34 drop down the resistances 25 and 25 respectively are cut out of the circuit. The cam I I in this system serves to raise the roller III once in its revolution and thereby allow the contacts 6, 1 to be opened by the camv 5 when the high part oi the cam comes beneath the roller 35. Y

In the operation of the system, we may assume initially that all of the. contacts are open as shown in the figure. As the disc 2 rotates in a clockwise direction, the roller 34 is the rst to drop down, allowing the contact 28 to close and cut out all of the resistances 25, 26 and 21. Following this, the contacts 6 and 1 are closed since the cam 5 moves faster than the cam I3 and thereby current is immediately applied to the solenoid 22.

This happening of events is so timed that the contact is applied immediately after the circuit through the solenoid 22 has been opened and the striker 2I.has hit the diaphragm. On account of the fact that the cam 5 rotates at approximately times the speed of the cam I3, it is possible to provide a very accurate timing for Aapplying the current to the solenoid 22 after the impact element has struck the diaphragm.

Following the closing of the contact 28, the

rollers 33 and 32 successively drop closing the contacts 29 and 30. Immediately when the contacts 6 and 1 are closed, the solenoid becomes energized and the striker is retracted against the force of the spring 23 until the striker is .raised to its highest position. As the cams I3,

I4 and I5 continue to rotate, the contact 28,is iirst opened putting in the resistance 25 and cutting down the current to the solenoid.

Following this the contact 25iis opened and the resistance 26 is added in the circuit and inally contact 3G is opened and the resistance 21 is added in the circuit. Shortly after this occurs, the roller Il rides on the high part of the cam II and drops the roller 55 at the other end of the arm 5 within 'the operating range of the cam 5. In that particular revolution, therefore, as the high part of the cam 5 comes beneath the roller 25, the contacts l and 1 are opened thus breaking the circuit and allowing the impact striker 2l to be driven against the diaphragm.

'I'he operation of the system is repeated in the manner described above as the roller 34 begins to drop down short-circuiting the resistances 25, 25 and 21.

In the description above it is stated that the circuit to thesolenoid was closed immediately afterthe impact. This perhaps should be more closely deiined. The cam 5 which serves to open the solenoid circuit at the critical time so that the impact will be produced when the indicator is at zero on the scale, serves also to close the circuit a little later. This closing is so timed that the striking element is being pulled upwards during its first rebound but not before or after.

Having now described my invention, I claim:

1. In a depth sounding system having a sound producer employing electrical means for retracting a striking element against the action of a spring and for releasing the striking element to strike a diaphragm when the energy supply is withdrawn, a method of preventing the striking element from rebounding and delivering a second blow to the diaphragm which comprises removing the supply of electrical energy for a period just short enough to allow the striking element to gain a free motion and applying the energy again to build up a force to withdraw the striking element as it leaves the diaphragm surface.

2. In a depth sounding system an oscillator having a diaphragm, a striker element spring means urging the latter element toward the diaphragm, and electromagnetic means for moving the striker element away from the diaphragm,

a circuit including/a source of current and said 

